A temperature control device for a fluid, which comprises a plurality of heating tanks, and which applies heat to fluid in these heating tanks, is per se known (for example, refer to Patent Document #1). With this type of temperature control device, a temperature sensor is provided to the outlet of each of the heating tanks, the outlet temperatures which have been measured are fed back with respect to a target temperature, and thereby control to the target temperature is performed with good accuracy.
Furthermore, as described in Patent Document #2, there is a temperature control device which only controls the outlet temperature of the heating tank which is farthest downstream, but does not perform temperature control for the other heating tanks, rather keeping the outputs of their heaters fixed.
[Patent Citation 1]
    Japanese Laid-Open Patent Publication Heisei 11-83175[Patent Citation 2]    Japanese Laid-Open Patent Publication Heisei 6-250743